/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

/* Some ICMP messages should be passed to the transport protocols. This
   is not implemented. */

#include <net/lwip/opt.h>

#if LWIP_ICMP					/* don't build if not configured for use in lwipopts.h */

#include <net/lwip/ipv6/icmp6.h>
#include <net/lwip/ipv6/inet6.h>
#include <net/lwip/ipv6/ip6.h>
#include <net/lwip/def.h>

void icmp_input(struct pbuf *p, struct netif *inp)
{
	u8_t type;
	struct icmp_echo_hdr *iecho;
	struct ip_hdr *iphdr;
	struct ip_addr tmpaddr;

	ICMP_STATS_INC(icmp.recv);

	/* TODO: check length before accessing payload! */

	type = ((u8_t *)p->payload)[0];

	switch (type) {
	case ICMP6_ECHO:
		LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));

		if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
			LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));

			pbuf_free(p);
			ICMP_STATS_INC(icmp.lenerr);
			return;
		}
		iecho = p->payload;
		iphdr = (struct ip_hdr *)((u8_t *)p->payload - IP_HLEN);
		if (inet_chksum_pbuf(p) != 0) {
			LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo (%" X16_F ")\n", inet_chksum_pseudo(p, &(iphdr->src), &(iphdr->dest), IP_PROTO_ICMP, p->tot_len)));
			ICMP_STATS_INC(icmp.chkerr);
			/*      return; */
		}
		LWIP_DEBUGF(ICMP_DEBUG, ("icmp: p->len %" S16_F " p->tot_len %" S16_F "\n", p->len, p->tot_len));
		ip_addr_set(&tmpaddr, &(iphdr->src));
		ip_addr_set(&(iphdr->src), &(iphdr->dest));
		ip_addr_set(&(iphdr->dest), &tmpaddr);
		iecho->type = ICMP6_ER;
		/* adjust the checksum */
		if (iecho->chksum >= htons(0xffff - (ICMP6_ECHO << 8))) {
			iecho->chksum += htons(ICMP6_ECHO << 8) + 1;
		} else {
			iecho->chksum += htons(ICMP6_ECHO << 8);
		}
		LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo (%" X16_F ")\n", inet_chksum_pseudo(p, &(iphdr->src), &(iphdr->dest), IP_PROTO_ICMP, p->tot_len)));
		ICMP_STATS_INC(icmp.xmit);

		/*    LWIP_DEBUGF("icmp: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len); */
		ip_output_if(p, &(iphdr->src), IP_HDRINCL, iphdr->hoplim, IP_PROTO_ICMP, inp);
		break;
	default:
		LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %" S16_F " not supported.\n", (s16_t)type));
		ICMP_STATS_INC(icmp.proterr);
		ICMP_STATS_INC(icmp.drop);
	}

	pbuf_free(p);
}

void icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t)
{
	struct pbuf *q;
	struct ip_hdr *iphdr;
	struct icmp_dur_hdr *idur;

	/* @todo: can this be PBUF_LINK instead of PBUF_IP? */
	q = pbuf_alloc(PBUF_IP, 8 + IP_HLEN + 8, PBUF_RAM);
	/* ICMP header + IP header + 8 bytes of data */
	if (q == NULL) {
		LWIP_DEBUGF(ICMP_DEBUG, ("icmp_dest_unreach: failed to allocate pbuf for ICMP packet.\n"));
		pbuf_free(p);
		return;
	}
	LWIP_ASSERT("check that first pbuf can hold icmp message", (q->len >= (8 + IP_HLEN + 8)));

	iphdr = p->payload;

	idur = q->payload;
	idur->type = (u8_t)ICMP6_DUR;
	idur->icode = (u8_t)t;

	SMEMCPY((u8_t *)q->payload + 8, p->payload, IP_HLEN + 8);

	/* calculate checksum */
	idur->chksum = 0;
	idur->chksum = inet_chksum(idur, q->len);
	ICMP_STATS_INC(icmp.xmit);

	ip_output(q, NULL, (struct ip_addr *)&(iphdr->src), ICMP_TTL, IP_PROTO_ICMP);
	pbuf_free(q);
}

void icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t)
{
	struct pbuf *q;
	struct ip_hdr *iphdr;
	struct icmp_te_hdr *tehdr;

	LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded\n"));

	/* @todo: can this be PBUF_LINK instead of PBUF_IP? */
	q = pbuf_alloc(PBUF_IP, 8 + IP_HLEN + 8, PBUF_RAM);
	/* ICMP header + IP header + 8 bytes of data */
	if (q == NULL) {
		LWIP_DEBUGF(ICMP_DEBUG, ("icmp_dest_unreach: failed to allocate pbuf for ICMP packet.\n"));
		pbuf_free(p);
		return;
	}
	LWIP_ASSERT("check that first pbuf can hold icmp message", (q->len >= (8 + IP_HLEN + 8)));

	iphdr = p->payload;

	tehdr = q->payload;
	tehdr->type = (u8_t)ICMP6_TE;
	tehdr->icode = (u8_t)t;

	/* copy fields from original packet */
	SMEMCPY((u8_t *)q->payload + 8, (u8_t *)p->payload, IP_HLEN + 8);

	/* calculate checksum */
	tehdr->chksum = 0;
	tehdr->chksum = inet_chksum(tehdr, q->len);
	ICMP_STATS_INC(icmp.xmit);
	ip_output(q, NULL, (struct ip_addr *)&(iphdr->src), ICMP_TTL, IP_PROTO_ICMP);
	pbuf_free(q);
}

#endif							/* LWIP_ICMP */
